Electronic devices such as laptop computers, cellular telephones, and other equipment are sometimes provided with optical components. For example, an electronic device may have an ambient light sensor for gathering measurements of ambient light levels. Ambient light information may be used in adjusting screen brightness during operation of an electronic device. If ambient light levels brighten, for example, display brightness can be increased to ensure that content is not obscured on a user's display.
Sensors such as ambient light sensors can be adversely affected by electrostatic charge when a user touches an electronic device near to the sensors. If care is not taken, signal perturbations from the presence of a user's finger can create noise in an ambient light sensor output signal. This can lead to undesired fluctuations in screen brightness.